Sweep panorama has become an innovative and exciting new method to acquire images on handheld digital image capture devices, such as digital cameras as well as devices such as mobile phones having a digital camera function. The panorama process involves the user holding the device in their hand and “sweeping” the device around a scene. Typically the user, holding the camera with the lens facing directly outwardly, swivels bodily through a desired angle to rotate the camera through typically a 180-360 degree field of view. During such sweep, multiple overlapping images are captured which are subsequently blended into a single, elongated image of the entire scene. An example of a prior art panorama acquisition is shown in FIGS. 1a and 1b. 
Examples of such panorama techniques are disclosed in WO2011069698 (Ref: P98956EP00/FN-352-EP) and WO2012032412 (Ref: P103053PC00/FN-352C-CIP-PCT) and in particular, these documents disclose techniques for blending component images of a panorama image together in real-time during image acquisition.
FIG. 1a shows a user 2 holding a camera 20 facing outwardly while he sweeps though about 180 degrees. FIG. 1b shows the actual scene 4 being captured and the camera 20 (in this case a mobile phone) part way through the sweep. The camera display screen 100 shows the current part of the view being scanned, as well as a so-called rectangular picture-in-picture (PiP) window 6 which is progressively filled from one end by a reduced sized image of the scene as successive overlapping images are captured.
The capabilities of these devices have been sufficiently enhanced to enable high quality image sequences to be blended during the acquisition process to present a high quality stitched image to the user practically in real-time.
However most current implementations fix the size of the sweep and while they show the user the progress of acquisition there is no way for the user to gain an understanding of how the size (length) of the sweep picture-in-picture (PiP) window relates to their actual sweep angle as they rotate the camera.
To take full advantage of the potential of sweep panorama imaging on today's touch interface cameras there is a need for a more advanced and interactive user interface that (i) enables users to easily configure and understand the size and geometry of the settings for a sweep panorama acquisition; and (ii) to view and monitor progress of the sweep during the acquisition process.